17-acyloxysteroids and their manufacture

ABSTRACT

WHERE R3 IS CHLORINE, BROMIDE, ALKANOYLOXY, AN ALKANESULPHONYOXY-OR ARENESULPHONYLLOXY-GROUP AND R1, A AND THE SYMBOL = ARE AS HEREINBEFORE DEFINED, AND THEREAFTER (A) REPLACING THE GROUP R3 BY HYDROGEN, THEN CONVERTING THE 17A-HYDROXYL GROUP INTO THE GROUP O.COR2 AND FINALLY REDUCING THE 11B-NITRATE GROUP TO AN 11BHYDROXYL GROUP; OR (B) CONVERTING THE 17A-HYDROXYL GROUP INTO THE GROUP O.COR*2, THEN REDUCING THE 11B-NITRATE GROUP TO AN 11B-HYDROXYL GROUP AND FINALLY REPLACING THE GROUP R*3 BY HYDROGEN; OR (C) CONVERTING THE 17A-HYDROXYL GROUP INTO THE GROUP O.COR2, THEN REPLACING THE GROUP R3 BY HYDROGEN AND FINALLY REDUCING THE 11B-NITRATE GROUP TO AN 11BHYDROXYL GROUP.   PHENANTHRENE AND ITS 5,6,9,10-DEHYDRO DERIVATIVE (III)   9-R1-1,2,3,4,4A,4B,5,6,7,9,10,10A-DODECAHYDRO   1,2-(-CH2-A-C(-OH)(-CO-CH2-R3),2-(CH3-),4(O2N-),7-(O=),   AND ITS 5,6 DEHYDRO DERIVATIVE (II)   9-R1-1,2,3,4,4A,4B,5,6,7,10A-DODECAHYDROPHENANTHRENE   1,2-(-CH2-A-C(-OH)(-CO-CH2-R3)-),2-(CH3-),4-(HO-),7-(O=),   THE INVENTION CONCERNS NOVEL STEROIDS HAVING VALUABLE PROPERTIES AS ANTI-INFLAMMATORY AGENTS IN VETERINARY AND HUMAN MEDICINE. THE NEW STEROIDS ARE 17A-ACYLOXY-B-HYDROXY PROGESTERONES AND THEIR $1, $6, $1,6, 21-HALO-$1 AND 21-HALO-$1,6 DERIVATIVES. PROCESSES FOR THEIR PREPARATION INCLUDE THE CONVERSION OF A COMPOUND OF THE GENERAL FORMULA II INTO THE CORRESPONDING 11B-NITRATE ESTER III,

United States Patent Ofice Patented Feb. 1, 1972 3,639,434 17-ACYLOXYSTEROIDS AND THEIR MANUFACTURE Peter Oxley and John Rosindale Honsley, Nottingham,

England, assignors to Boots Pure Drug Company Limited, Nottingham, England No Drawing. Filed Feb. 2, 1967, Ser. No. 613,454 Int. Cl. C07c 169/32 US. Cl. 260397.45 2 Claims ABSTRACT OF THE DISCLOSURE The invention concerns novel steroids having valuable properties as anti-inflammatory agents in veterinary and human medicine.

TIhe new steroids are 170: .acyloxy-fi-hydroxy progresterones and their A A", A 21-halo-A and 21-halo-A derivatives. I

Processes for their preparation include the conversion of a compound of the general Formula H into the corresponding llfI-nitrate ester IH,

3 fil co H H a" o? oloolII Ins-III where R is chlorine, bromide, alkanoyloxy, an alkanesulphonyloxyor arenesulphonyloxy-group and R A and the symbol: are as hereinbefore defined, and thereafter This invention relates to esters of steroids and processes for preparing them. More particularly it relates to the preparation of 170: acyloxy-llfi-hydroxy-progesterones and their A A and M -derivatives. The invention also relates to novel l7a-acyloxy-1lfl-hydroxy-progesterones and their 13 A and A derivatives and to therapeutic compositions thereof. The invention also relates to a method of treating inflammation, especially inflammation of the skin in animals including man.

The use of corticosteroids in the treatment of inflammatory conditions by oral, parenteral or topical administration is well-known. It has recently been discovered that the topical anti-inflammatory activity of steroids may be enhanced by acylation of the 17a-hydroxyl group, a. particularly active example of this type of compound being betamethasone 17a-valerate. Many anti-inflammatory steroids contain 11 fi-hydroxyl groups in the molecule and although methods are available for preparing l7a-acyloxyderivatives of llfi-hydroxy-steroids in which there is also a 21-hydroxyl group, e.g. by hydrolysis of the 1741-21- ortho-ester, there is no method generally applicable to all 11 5,17 a-dihydroxy-steroids. This is because of the similar reactivities of the llfl-hydroxy group and the 170:- hydroxyl group.

In British patent application 6,215/65 we have claimed a process for preparing l7-esters of 11fl,17a-dihydroXypregnanes having a substituent at C comprising protecting the 11,3 hydroxyl substituent with a nitrate ester group, acylating the l7a-hydroxyl group, removing the protecting group by a non-hydrolytic process and isolating the 17a-acyloxy-1lfl-hydroxy-steroid.

Although this process may be applied to l1;8,17a-dihydroxyprogesterones, there is much less difference between the reactivity of the llfland 17a-hydroxyl groups in pregnanes without a C substituent; it is diflicult to separate the llfi-nitrate from the 17a-nitrate and the 11; 17a-dinitrate which is the major product. Economic yields of 1700 acyloxy 11B hydroxyprogesterones cannot be achieved by this method.

We have now discovered novel processes for preparing l7u-acyloxy-llfl-hydroxy steroids of the pregnane series. We have also discovered novel 17a-acyloXy-11B-hydroXyprogesterones having valuable therapeutic activity.

According to the present invention there is provided a process for preparing a compound of the general Formula I.

( 0 OCOR where the bonds marked may be either a single or a double bond. A represents the groups 3 CH R where R is chlorine, bromine, alkanoyloxy, an alkanesulphonyloxyor arenesulphonyloXy-group and R A and the symbol are as hereinbefore defined, and thereafter (a) replacing the group R by hydrogen, then converting the 17a-hydroxyl group into the group O-COR and finally reducing the llfi-nitrate group to an llfi-hydroxyl group; or

(b) converting the 17a-hydroxyl group into the group O-COR then reducing the 1l/3-nitrate group to an llfi-hydroxyl group and finally replacing the group R by hydrogen; or

(c) converting the l7a-hydroxyl group into the group O-COR then replacing the group R by hydrogen and 3 lfinally reducing the llfl-nitrate group to an llfi-hydroxyl group.

Under certain reaction conditions replacement of the R group by hydrogen and reduction of the llfi-nitrate group in steps (b) and may take place simultaneously.

There are also provided novel therapeutic compositions containing as active ingredient a compound of the general Formula IV:

a co 9.101;-

where R and the symbol: are as hereinbefore defined provided that at least one of the 1,2- and 6,7-linkages is a double bond, in association with a pharmaceutically acceptable diluent or carrier.

There are also provided novel intermediates comprising prednisolone llB-nitrate and compounds of general Formula V;

where R is hydrogen, bromine or iodine, R is hydrogen or the group COR and R R A and the symbolr. are as hereinbefore defined.

There are also provided novel compounds of general Formula IV with the exception of 21 desoxy-prednisolone 17a-acetate.

Preferred compounds of general Formula IV are those in which R is alkyl (C -C 'Ihe nitrate ester group, of compounds of general Formula III, which is conveniently introduced by the action of acetyl nitrate, a reagent produced by mixing fuming nitric acid with acetic anhydride, is most conveniently transformed into hydroxyl by reduction with zinc and acetic acid.

The acylation of the 17a-hydroxy group may be achieved by reaction with an alkanoic acid anhydride (R CO) O or an acid halide R COX where X is chlorine or bromine in the presence of a suitable strong acid catalyst. The preferred catalyst is p-toluenesulphonic acid but acids such as perchloric acid are also suitable. The acylation may also be catalysed by bases such as triethyl amine. Another method of acylation employs an alkanoic acid R COOH in the presence of trifluoroacetic anhydride. 17a-acetates only may be prepared by reaction of the l7u-hydroxy compound with ketene, preferably in the presence of an acid catalyst.

The group R is replaced by hydrogen using conventional methods. For example, a preferred group is the methanesulphonyloxy-group which is readily reduced with sodium iodide and acetic acid. When R is chlorine, bromine or iodine the halogen may be replaced with hydrogen using zinc and acetic acid.

For convenience, compounds of general Formula IV are referred to as 21-desoxyhydrocortisones and 2l-desoxyprednisolones hereafter.

The compounds of general Formula IV have been found to have valuable anti-inflammatory activity and to be particularly valuable for topical application. For example wehave tested 2l-desoxyprednisolone l7a-propionate by the McKenzie test (Archives of Dermatology, 1962, 86, 608-610) and found it to be several times as active as triamcinolone acetonide, a commercially avail- 4 able steroid for topical application. The unacylated steroid, 21-desoxyprednisolone, however, is virtually inactive in the McKenzie test.

In the following typical reaction schemes, the preparation of 2l-desoxyprednisolone series is illustrated but this is not to be construed as limiting and is by way of example only.

The compound VI may be converted into the ll-nitrate VII by treatment with acetyl nitrate. This compound may be converted into the 2l-desoxy-compound VIII, which in turn is acylated to give the l7-acylate IX. This compound may also be prepared by-converting compound VII into the 17-acylate, X and subsequently treating with sodium iodide in acetic acid to give the compound D(. Compound IX is finally converted into compound XI by treatment with zinc dust and acetic acid. Compound X may also be reduced with zinc and acetic acid to give compound XII which gives compound XI when treated with sodium iodide in acetic acid. In another modification, prednisolone 21-acetate (XIII) may be converted into the llp-nitrate (XIV) which is then hydrolysed to prednisolone llfi-nitrate (XV). Compound XV is converted into compound VII by reaction with methanesulphonyl chloride in the presence of a base such as pyridine. Compound X may be converted into the corresponding 21-iodide which may be reduced to comcompound XI using zinc dust and acetic acid. Similarly, compound XII may be converted into the corresponding 2l-iodide which may be reduced to compound XI.

Acetvl nitrate NI'cet'c 3 lulu 1 co ocou CH OSO CH Cli In an alternative process prednisolone 17 acylates (XVI) are converted into the 21 methanesulphonates (XII) which are treated with sodium iodide and acetic acid to give the corresponding 21-desoxy 17 acylates (XI). Alternatively, the compounds XII may be converted into the 2l-chloro-compounds (XVII) by treatment with lithium chloride in dimethylformamide; these compounds are reduced, for example with zinc dust and acetic acid, to give the compounds XI.

CH O S E1 (XVIII) is converted into its ZI-methanesulphonate (V-I) which is treated with lithium chloride in dimethylformamide to give the corresponding 21 chloro-compound (XIX). Treatment with acetyl nitrate gives the ll-nitrate (XX) which is treated with an acid anhydride (R CO) O in the presence of p-toluenesulphonic acid to give the 17- esters (XXI). Reduction with zinc dust and acetic acid gives the corresponding 21-desoxy 17 acylates (XI). Prednisolone 2l-bromide may be converted into the 21- desoxy-17-acylates (XI) by a similar process.

nitrate -In a further process compounds of the general Formula XI may be prepared by reduction of a 9u-halocompound (XXII) with chromous acetate in the presence of an alkane thiol and preferably in dimethylsulphoxide as solvent.

cc ,ccon co econ".

no i chromous acetate] ")0 g butanethiol where R is chloride or bromine and R is as hereinbefore defined.

The hydrocortisones or the M-analogues of the prednisolone series exemplified in these typical reaction schemes using llfl-nitrate intermediates may be made by similar reactions but starting with a A -steroid instead of a A -steroid. The intermediates and the final products of the above typical reaction schemes in the hydrocortisome series may be dehydrogenated at C and C by conventional methods, for example microbiological oxidation Ill].

provided that R is not acyloxy. Suitable organisms for such dehydrogenation at C and C include Corynebacterium simplex, Bacillus sphaericus and Septomyxa aflinis. Unsaturation at C and C may also be introduced by chemical oxidation, an especially useful dehydrogenating agent being 2,3-dichloro-5,6-dicyanobenzoquinone.

The compounds of the hydrocortisone and prednisolone series are most conveniently converted into the corresponding A and A -compounds respectively by chemical dehydrogenation using tetrachlorobenzoquinone.

The preferred compositions according to the present invention comprising a compound of general Formula IV in association with a pharmaceutically acceptable diluent are those adapted for topical application although the invention is not to be considered to be limited to such compositions. Such compositions may be in the form of liquid solutions or suspensions or in the form of semi-solid creams and ointments.

The compositions may also contain additional therapeutic agents which are compatible with the compounds of general Formula IV and which are pharmaceutically acceptable. Particularly valuable additional therapeutic agents include antibacterial agents such as neomycin, 2-bromo-2-nitropropane-l,3-diol, 5-chloro 8 hydroxy- 7-iodoquinoline and 5,7-dichloro-8-hydroxyquinoline.

The following non-limitative examples illustrate the invention. For convenience, trade names are used for certain materials and these are identified as follows:

Florisil-Registered trademark for a synthetic magnesia/ silica gel adsorbent.

Kieselgel GA trade name for a silica gel adsorbent.

PolawaxA trade name for a polyoxyethylene sorbitan ester emulsifying agent.

Freon 1l--A trade name for the propellant trichlorofiuoromethane.

Freon 12A trade name for the propellant dichlorodifluoromethane.

Freon 114A trade name for the propellant 1,2-dich1oro- 1,1,2,2-tetrafluoroethane.

The content of the ingredients of compositions is percent w./w. unless there is a statement to the contrary.

EXAMPLE 1 Prednisolone 21-methanesulphonate (10 g.) was added to a stirred solution of acetyl nitrate at 0 C. prepared from glacial acetic acid ml.) acetic anhydride (100 ml.) and fuming nitric acid (20 ml.). The steroid had dissolved after 1 /2 hours and after 4 hours the mixture was poured into ice/water (1000 ml.). The product was collected in methylene chloride, the extract was washed with water, dried and evaporated. The residue was crystallised from benzene to give a benzene solvate of prednisolone ZI-methanesulphonate llfl-nitrate, MP. 177 C. (dec.).

Prednisolone ZI-methanesulphonate llB-nitrate (4 g.) dissolved in acetic acid (80 ml.) was stirred with sodium iodide (8 g.) at room temperature for 1 hour. 5% sodium bisulphite solution (80 ml.) was added to the mixture followed by water (80 ml.) until a slight turbidity was apparent. The product crystallised on seeding to give 2l-desoxyprednisolone H S-nitrate, M.P. 144-145" C. (dec.). It was used for esterification without further purification.

Toluene-p-sulphonic acid (50 mg.) was dissolved in isobutyric anhydride (2 ml.), 21-desoxyprednisolone 11B- nitrate (500 mg.) was added and the suspension was warmed to 80 C. for 30 minutes. The clear solution was cooled and the crystals which separated were collected and washed with ether to give 2l-desoxyprednisolone 17aisobutyrate 1 lfi-nitrate, M.P. 196 C. (dec.), [ab .+76.1 (chloroform). Found (percent): C, 65.5; H, 7.1. C H NO requires (percent): C, 65.3; H, 7.2.

The above compound (400 mg.) was dissolved in acetic acid (20 ml.) and stirred for 15 minutes with zinc dust (2 g.). The mixture was filtered, the filtrate was diluted with water and the product was collected in benzene. The solution was washed with water, evaporated to dryness and the residue was triturated with ether. Further purification by chromatography gave 21-desoxyprednisolone 17a-isobutyrate, M.P. 220-221 C., [ab +33.2 (chloroform). Found (percent): C, 72.4; H, 8.4. C H O requires (percent): C, 72.4; H, 8.3.

In a similar way there were prepared:

21-desoxyprednisolone 11,8-nitrate 17a-propionate, M.P.

205 C. (dec.), [01],; +69.5 (chloroform).

21-desoxyprednisolone 17a-propionate, M.P. 228-229 C., [i11 +34.0 (chloroform). (Found (percent): C, 72.0; H, 8.2. C H O requires (percent): C, 72.0; H, 8.0.)

2l-desoxyprednisolone 11,6-nitrate 17apivalate, M.P. 197- 198 C. (dec.), [aJ +67.3 (chloroform).

2l-desoxyprednisolone 17a-pivalate, M.P. 270-271 C., [a] +33.0 (chloroform). (Found (percent): C, 72.5; H, 8.7. C H O requires (percent): C, 72.9; H, 8.5.)

2l-desoxyprednisolone Il s-nitrate 17m-valerate.

21-desoxyprednisolone 17a-valerate, M.P. 200 C., [041 +31.9 (chloroform). (Found (percent): C, 72.7; H, 8.5. C H O requires (percent): C, 72.9; H, 8.5)

2l-desoxyprednisolone 17a-hexanoate Il s-nitrate.

21-desoxyprednisolone 17a-hexanoate, M.P. 158159 C., [0:1 +30.7 (chloroform). (Found (percent): C, 73.7; H, 8.9. C H O requires (percent): C, 73.3; H, 8.7.)

2l-desoxyprednisolone 17a-cyclobutanecarboxylate 1113- nitrate, M.P. 203-204 C. (dec.), +67 (chloroform. (Found (percent): C, 66.3; H, 7.3; N, 2.7. C H NO requires (percent): C, 66.2; H, 7.1; N, 3 0

21-desoxyprednisolone 17a-cyclobutanecarboxylate M.P. 266-269 C. (dec.), [0:]5 +34 (chloroform). (Found (percent): C, 73.6;H, 8.1. C H O requires (percent): C, 73.2; H, 8.0.)

21-desoxyprednisolone 17a-cyclopropanecarboxylate 1118- nitrate M.P. 200 C. (dec.), [11],? +57 (chloroform). (Found (percent): C, 65.4; H, 7.0; N, 2.8. C H NO requires (percent): C, 65.6; H, 6.8; N, 3.1.)

21 desoxyprednisolone 17c: cycloprop'anecarboxylate M. P. 255-257 C. (dec.), +26 (chloroform). (Found (percent): C, 72.7; H, 7.9. C H O requires (percent): C, 72.8; H, 7.8.)

2l-desoxyprednisolone 17a methoxyacetate 113 nitrate M.P. 164-165 C., [431 +62 (chloroform). (Found (percent): C, 62.5; H, 6.8; N, 2.9. C H NO requires (percent): C, 62.5; H, 6.8; N, 3.0.)

21 desoxyprednisolone 17a methoxyacetate, M.P. 230- 232 C., [0:],5 +29 (chloroform). (Found (percent): C, 68.8; H, 7.9. C ,,H O- requires (percent): C, 69.2; H, 7.8.)

21-desoxyprednisolone l7a-benzoate llfl-nitrate M.P. 200202 C. (dec.). (Found (percent): C, 67.0; H, 6.3; N, 2.7. C28H31NO7, %H O requires (percent): C, 66.9; H, 6.4; N, 2.8.)

zl-desoxyprednisolone l7a-benzoate M.P. 279-280 C., [u] -2 (chloroform). (Found (percent): C, 14.6; H, 7.3. C H O requires (percent): C, 75.0; H, 7.2.)

21-desoxyprednisolone 17a-crotonate lip-nitrate M.P.

175-177" C. (dec.), +39 (chloroform).

(Found (percent): C, 66.0; H, 6.7. C25H31NO'1 requires (percent): C, 65.6; H, 6.8.)

21-desoxyprednisolone 17a-crotonate M.P. 275-276 C. (dec.), (chloroform). (Found (percent): C, 73.1; H, 7.9. C H O requires (percent): C, 72.8; H, 7.8.)

2l-desoxyprednisolone l7a-acrylate 11B-nitrate M.P. 213- 215 C. (dec.), [0;]; +69 (chloroform). (Found (percent): C, 64.9; H, 6.8. C H NO requires (percent): C, 65.0; H, 6.6.)

2l-desoxyprednisolone 17a-acrylate M.P. 245-247 C. [111 +2 (chloroform). (Found (percent): C, 69.4; H, 7.6. C H O .H O requires (percent): C, 69.2; H, 7.8.) I

2l-desoxyhydrocortisone llfi-nitrate M.P. l7ll74 C., [111 +179 (chloromorm). (Found (percent): C, 64.3; H, 7.6; N, 3.9; C H NO requires (percent): C, 64.4; H, 7.5; N, 3.6.)

2l-desoxyhydrocortisone llfl-nitrate 1706-PI'OP1OI13I6.

2l-desoxyhydrocortisone 17a-propionate M.P. 225-228 C., identical with that prepared by the method of Example 2.

2 l-desoxy-16a-methylhydrocortisone 115 nitrate,

21-desoxy-16u-methylhydrocortisone 11p nitrate 17ozpropionate.

ZI-dCSOXY-16oc methylhydrocortisone 17a propionate, M.P. 244-249 C. (Found (percent): C, 72.2; H, 8.6. C H O requires (percent): C, 72.1; H, 8.7.)

2l-desoxy-6a-methylprednisolone llfi-nitrate M.P. 190

C. (dec.), [131 +100 (chloroform). (Found (percent): C, 65.6; H, 7.4. C H NO requires (percent): C, 65.5; H, 7.2.)

21-desoxy-6a methylprednisolone 11 pi nitrate 17a propionate.

21-desoxy-Ga-methylprednisolone .17 propionate, M.P.

222-223 C., [:31 +205" (chloroform). (Found (percent): C, 71.9; H, 8.3. C H O requires (percent): C, 72.4; H, 8.3.)

21-desoxy-mat-methylprednisolone l7u-acetate ll-fi-nitrate.

21-desoxy-6a-methylprednisolone 17u-acetate, M.P. 249- 250 C., [a1 +22.3 (chloroform). (Found (percent): C, 72.0; H, 8.2. C H O requires (percent): C, 72.0; H, 8.0.)

2l-desoxy 6a methylprednisolone 17o: isobutyrate llfinitrate.

21-desoxy-6eat-methylprednisolone 17a-isobutyrate, M.P.

l94195 C., [11],; +21.5 (chloroform). (Found (percent): C, 72.5; H, 8.2. C H 0 requires (percent): C, 72.9; H, 8.5.)

EXAMPLE 2 A mixture of prednisolone (20 g.), methyl orthophenylacetate (24 ml.), and dimethylformamide (24 ml.) was heated to C., treated with p-toluene-sulphonic acid (240 mg.) and distilled slowly in vacuo for 15 minutes. Pyridine (1 ml.) was added and the solvents were removed by distillation in vacuo. The solid obtained after trituration with acetone was recrystallised from chloroform-methanol to give rods of prednisolone 17a,21-methyl orthophenylacetate, M.P. 198-199 C., [a] +l01 (dioxan, c.'=1.06). (Found (percent): C, 73.15; H, 7.5. C H O requires (percent): C, 73.2; H, 7.4.)

A suspension of this compound (2 g.) in methanol (20 ml.) was warmed to 45 C., and treated with M-oxalic acid (3 ml.). After 5 minutes at 4548 C., the solution was diluted with water and the oily product isolated with methylene chloride. crystallisation from acetone/ether gave needles of prednisolone 17a-phenylacetate, M.P. -177 C., +23 (dioxan, c.=1.055). (Found (percent): C, 73.0; H, 7.2. C H ,O requires (percent): 0, 72.8; H, 7.2.)

A mixture of this compound (7 g.) and dry pyridine (30 ml.) was cooled to 0 C. and treated with methanesulphonyl chloride (1.6 ml.). After 5 hours at room temperature the mixture was diluted with water and the product isolated with methylene chloride. Crystallisation from methylene chloride/acetone gave elongated prisms of prednisolone ZI-methanesulphonate 17a-phenylacetate, M.P. 207-208 C. (dec.), [@1 +37 (dioxan, c.=1.1). (Found (percent): C, 64.7; H, 6.6. C H O S requires (percent): C, 64.7; H, 6.5.)

A mixture of this steroid (500 mg), sodium iodide (2 g.) and glacial acetic acid (24 ml.) was heated on the steam bath for 24 hours. After dilution with 2% aqueous sodium thiosulphate, the product was isolated with chloroform and crystallised from acetone/ether/hexane to give flat prisms of 21-desoxyprednisolone 17a-phenylacetate, M.P. 200202 C., [u] +80 (chloroform, c.=0.59). (Found (percent): C, 75.5; H, 7.5. C H O requires (percent): C, 75.3; H, 7.4.)

in a similar way, the following compounds were prepared from the appropriate 17a-ester of hydrocortisone or prednisolone.

2l-desoxyhydrocortisone -1OL-3C6tfltfi, M.P. 253-256 CL, [a] +97 (chloroform). (Found (percent): 0, 71.3; H, 8.5. C H O requires (percent): C, 71.1; H, 8.3.)

21-desoxyhydrocortisone 17a-propionate, M.P. 227230 C. (dec.), [a] +96 (chloroform). (Found (percent): C, 71.4; H, 8.7. C H O requires (percent): C, 71.6; H, 8.5.)

21-desoxyprednisolone 17a-propionate, identical with that prepared by the method described in Example 1.

EXAMPLE 3 Prednisolone 21'chloride, M.P. 238240 C. (dec.), [oz] +145 (ethanol, c.=0.78), (2 g.), was added to a stirred ice-cold solution of acetyl nitrate prepared at C. from acetic acid (20 ml.), acetic anhydride (16 ml.), and fuming nitric acid (4 ml.). After 2 hours at 0 C., the solution was poured on ice/ water and the pale yellow solid collected by filtration. The air-dried product was chromatographed on a column of Florisil (100 g.). 10% v./v. acetone in hexane eluted material which crystallised from acetone/hexane to give flat rhombs of prednisolone 21-chloride llfi-nitrate, M.P. 192.5194.5 C., +167 (chloroform, c.=0.42). (Found (percent): C, 59.1; H, 6.2; CI, 8.3; N, 3.3. C H ClNO requires (percent): C, 59.5; H, 6.2; Cl, 8.4; N, 3.3.)

A suspension of this compound (1.18 g.) in acetic anhydride (30 ml.) containing p-toluenesulphonic acid (0.3 g.) was stirred overnight at room temperature, poured into ice/water, and the mixture stirred for 1 hour. The product was isolated with chloroform and chromatographed on a column of Florisil (50 g.). 10% v./v. acetone in hexane eluted material which crystallised from acetone/hexane to give elongated plates of prednisolone 17a-acetate 21-chloride llji-nitrate, M.P. 199201 C. (dec.), [M +85 (chloroform, c.=1.03). (Found (percent): C, 59.6; H, 5.9; CI, 7.5. C H ClNO requires (percent): C, 59.3; H, 6.1; Cl, 7.6.)

A solution of this compound (0.4 g.) in glacial acetic acid (40 ml.) was stirred with zinc dust (4 g.) for minutes, filtered, and the filtrate evaporated to a low bulk in vacuo. Dilution with water and isolation with chloroform gave a mixture which was separated by preparative thin layer chromatography on Kieselgel G with 5% v./v. methanol in chloroform as solvent. The least mobile component was eluted from the adsorbent with ethyl acetate and crystallised from methanol to give elongated prisms of 21-desoxyprednisolone Hot-acetate, M.P. 259-261 C., [06113 +34 (chloroform, c.=0.44). (Found (percent): C, 71.45; H, 7.9. C H O' requires (percent): C, 71.5; H, 7.8.)

EXAMPLE 4 In a similar way to that described in Example 2, prednisolone 17a-butyrate, M.P. 2172l9 0., +1.2 (dioxan, c.='0.825), was converted into prednisolone 17abutyrate 21-methanesulphonate, M.P. 120-123" C., +26 (dioxan, c.=1.4). (Found (percent): C, 61.0; H, 7.2. C H O S requires (percent): C, 61.4; H, 7.1.)

In a similar way to that described in Example 2, this compound was converted into '21-desoxyprednisolone 17abutyrate which crystallised from acetone/hexane as prisms, M.P. 232-235 C., [a] +36 (chloroform, c.=0.3). (Found (percent): C, 72.2; H, 8.3. C H 4O requires (percent): C, 72.45; H, 8.3.) i

Similarly, prednisolone 17a-propionate was converted via prednisolone ZI-methanesulphonate 17a-propionate, M.P. -137 C. (dec.), into 21-desoxyprednisolone 17a-propionate.

EXAMPLE 5 A mixture of glacial acetic acid (94 ml.) and acetic anhydride (94 ml.) was cooled to 0 C., and stirred for 15 minutes during the addition of fuming nitric acid 18.8 ml.) and left to stand for a further 15 minutes. Prednisolone 21-acetate (10.5 g.) was added and the mixture was stirred for 2 /2 hours at 0 C. The solution was poured on ice and the product was isolated with methylene chloride. It was crystallised from benzene to give prednisolone 21-acetate llfi-nitrate, M.P. 198-201 C. (dec.), [M +156.5 (dioxan, c.=1.2). (Found (percent): C, 61.9; H, 6.7. C H NO requires (percent): C, 61.7; H, 6.5.)

Prednisolone 21-acetate 11/3-nitrate (500 mg.) was added to a solution of potassium cyanide (20 mg.) in methanol (5 ml.) and the suspension was left to stand at room temperature with occasional shaking. After 3 hours, solution was complete and it was left to stand overnight. The solution was neutralised with'acetic acid and diluted with water (5 ml.) to give hydrated crystals of prednisolone llB-nitrate, M.P. 172173 C., (dec.), [1x1 (chloroform). (Found (percent): C, 61.3; H, 7.1. C H NO /2H 0 requires (percent): C, 60.9; H, 6.8.)

Prednisolone llfl-nitrate (200 mg.) was dissolved in 2,6-lutidine (2 ml.), methanesulphonyl chloride (0.1 ml.) was added and the mixture was left to stand for 1 hour at room temperature. The mixture was poured into N-hydrochloric acid (50 ml.), the solid which separated was collected, washed with water, dried and crystallised from benzene to give prednisolone 21-methanesulphonate 11/5- nitrate, identical with that described in Example 1.

EXAMPLE 6 21 desoxyprednisolone 115 nitrate 17a propionate (71.8 g.), prepared as in Example 1, was dissolved in methylene chloride (3600 ml.) and glacial acetic acid (360 ml.) was added. After cooling to 3 C., zinc dust (360 g.) was added portionwise over 20 minutes with stirring which was continued for a further 20 minutes after the addition of the zinc. The mixture was filtered, the filtrate was washed with aqueous potassium carbonate solution and water, then dried and evaporated to 100 ml. Acetone (350 ml.) was added, 200 ml. of solvent was distilled off and the concentrate was cooled to 5 C., seeded and diluted with hexane (250 ml.) when crystallisation started. The crystals were collected, washed with ether and light petroleum (B.P. 4060 C.) to give 21- desoxyprednisolone 17a-propionate, M.P. 227229 C., identical with that produced by the method of Example 1.

EXAMPLE 7 21 desoxyprednisolone 11B nitrate 17a propionate (445 mg.), prepared as in Example 1, was suspended in dry methanol (45 ml.) and the suspension was added to a pre-reduced suspension of palladium oxide (80 mg.) in dry methanol 10 ml.). The mixture was shaken under hydrogen when 16 ml. was absorbed in 30 minutes. The mixture was filtered, and the filtrate was evaporated to give a gum which was shown to contain 21-des0xyprednisolone 17a-propionate by thin layer chromatography.

EXAMPLE 8 A solution of 21-desoxyprednisolone llB-nitrate 17apropionate (0.5 g.) in methylene chloride (25 ml.) was stirred at reflux temperature with tin (2.5 g.) and concentrated hydrochloric acid for 5- /2 hours. Thin layer chromatography indicated an approximately 40% yield of 21-desoxyprednisol0ne 17a-propionate.

1 1 EXAMPLE 9 A suspension of zinc amalgam (2.5 g.) in dioxan (20 ml.) was stirred with cooling until freezing began, cooling was stopped, 21-desoxyprednisolone 11/8-nitrate 17apropionate (0.5 g.) and water (0.5 ml.) were added, and the mixture was stirred at 810 C. for 1 hour. Thin layer chromatograms indicated that the major product was 21-de-soxyprednisolone 17otpropionate.

EXAMPLE 10 Aluminium turnings (5 g.) were amalgamated with 5% aqueous mercuric chloride solution and suspended in anhydrous methanol. A suspension of 21-desoxyprednisolone llfi-nitrate 17ot-propionate (1 g.) in methanol (20 ml.) was added. Reaction was initiated by addition of water (0.75 ml.) and dioxan (20 ml.) and the mixture was refluxed for 1 hour. Thin layer chromatograms indicated partial conversion into 21-desoxyprednisolone 17a-propionate.

EXAMPLE 11 Dimethylformamide (10 ml.) and 21-desoxyprednisolone H S-nitrate 17a-propionate (0.5 g.) were added to a. mixture of granulated zinc (2.5 g.) and glacial acetic acid (10 ml.). The temperature rose from 5 C. to 37 C. and, after 30-40 minutes, thin layer chromatograms indicated a 60% conversion into 21 desoxyprednisolone 17u-propionate.

EXAMPLE 12 Prednisolone ZI-methanesulphonate Il s-nitrate (5. g.), prepared as in Example 1, sodium iodide (5 g.) and acetone (60 ml.) were refluxed for 45 minutes and the cooled mixture was poured into water. The mixture was extracted with methylene chloride, the clear organic phase was collected, washed with water, dried and evaporated to about 10 ml. The solution crystallised on cooling to C. to give prednisolone 2l-iodide llfi-nitrate, M.P. 175176 C. (dec.), [0:1 :9 +138 (dioxan). (Found (percent): C, 49.3; H, 5.4; I, 24.3; N, 2.5. C H 1NO requires (percent): C, 48.9; H, 5.1; I, 24.6; N, 2.7.)

This compound (100 mg.) in dioxan ml.) was stirred with 10% aqueous sodium hydrogen sulphite (2 ml.) for 1 /2 hours at room temperature, and then poured into water. The mixture was extracted with methylene chloride, the extract was washed and dried and the solvent was evaporated. The residue was crystallised from ether to give 2l-desoxyprednisolone llfl-nitrate, M.P. 142-147 C., identical with material prepared as described in Example 1.

This compound was converted into 2l-desoxyprednisolone 17u-propionate as described in Example 1.

EXAMPLE 13 Prednisolone 2l-methanesulphonate llfi-nitrate (1 g.), prepared as in Example 1, sodium bromide (1 g.) and acetone (12 ml.) were refluxed for 3- /2 hours, the cooled mixture was poured into water and extracted with chloroform. The extract was dried, evaporated and the residue was crystallised from chloroform/methanol to give prednisolone 21-bromide 11 p-nitrate, M.P. 189-190 C., [0:1 149 (chlorofrom), identical with that prepared by the method of Example 14. It was converted into 21- desoxyprednisolone 17a-propionate as described in Example 14.

EXAMPLE 14 Prednisolone 2l-bromide (2 g.) was added to acetyl nitrate prepared from acetic acid ml.), acetic anhydride (16 ml.) and fuming nitric acid (4 ml.) at 0 C., the mixture was stirred at O9 C. for 1 hour then warmed to room temperature and stirred for 2 hours. The mixture was poured into water, extracted with methylene chloride, the extract was washed with aqueous sodium bicarbonate solution, then water, and dried. The solvent was evaporated and the residue was dissolved in chloro- This compound (884 mg.) was added to p-toluenesul-' phonic acid (18 mg.) in propionic anhydride (1.8 ml.), chloroform (13 ml.) was added and the mixture was refluxed overnight. The mixture was cooled, stirred for 1% hours with water (8 ml.) and ammonium hydroxide (SG 0.88, 4 ml.) and the solvent layer was collected. It was washed with water, dried, evaporated and the residue was crystallised from acetone to give prednisolone 21- bromide llfl-nitrate 17a-propionate, M.P. 198-200 C. (dec.), +101 (chloroform). (Found (percent): C, 55.1; H, 5.7; Br, 15.5; N, 2.6. C H BrNO requires (percent): C, 55.0; H, 5.8; Br, 15.2; N, 2.7.)

This compound (200 mg.) in methylene chloride (8 ml.) was stirred with zinc dust (1 g.) at 5l0 C. during the dropwise addition of a solution of acetic acid (0.27 ml.) in methylene chloride (2 ml.). After 10 minutes at 10 C., the solution was kept at room temperature for 10 minutes and filtered. The filtrate was washed with dilute aqueous sodium bicarbonate, then water, dried and evaporated. The residue was purified by preparative layer chromatography and crystallised from methylene chloride/ ether to give 21-desoxyprednisolone 17a-propionate, M.P. 229-231 C., identical with that prepared by the method described in Example 1.

EXAMPLE 15 A mixture of p-toluenesulphonic acid (100 mg.), propionic anhydride (10 ml.) chloroform ml.) and prednisolone 21-methanesulphonate llfi-nitrate (5 g.), prepared as in Example 1, was refluxed for 3 days, cooled and stirred for 1 /2 hours with Water (40 ml.) and ammonium hydroxide (SG 0.88, 20 ml.) The solvent layer was collected, washed with Water, dried and evaporated. The residual gummy prednisolone 21-methanesulphonate 11/3-r1itrate 17a-propionate (6.6 g.) in methylene chloride (265 ml.) was stirred at 5 C. with zinc dust (33 g.) during the dropwise addition of acetic acid (9 ml.) in methylene chloride (25 ml.). After 30 minutes at 10 C. the mixture was warmed to room temperature, left at room temperature for a short time, filtered and the filtrate was washed with aqueous sodium bicarbonate and dried. The solvent was evaporated and the residue was crystallised from methanol to give prednisolone 21- methanesulphonate 17u-propionate, M.P. 134137 C., identical with that prepared by the method of Example 4.

A solution of prednisolone 2l-methanesulphonate 17apropionate (1 g.) in dimethylformamide (12 ml.) was heated on the steam-bath with sodium bromide (1 g.) for 7 hours, cooled, poured into water, and extracted with methylene chloride. The extract was percolated through Florisil (registered trademark). Elution was continued with 20% acetone in chloroform (200 ml.). The total eluate was evaporated and the residue was crystallised from acetone to give prednisolone 2l-bromide 17apropionate, M.P. 204-205 C. (dec.), [11 +82 (chloroform) This compound (200 mg.) in methylene chloride (16 ml.) was stirred with zinc dust (2 g.) at 510 C. during the dropwise addition of glacial acetic acid (0.54 ml.) in methylene chloride (4 ml.). After a further 10 minutes at 10 C. the mixture was warmed to room temperature for 10 minutes, cooled, filtered and the filtrate was washed with aqueous sodium bicarbonate solution and then water. The dried solution was evaporated and the residue was crystallised from acetone/hexane to give 2l-desoxyprednisolone l7vx-propionate authentic material.

identical with 13 EXAMPLE 16 A solution of prednisolone (20 g.) in dry pyridine (100 ml.) was stirred at -2 C. during the addition of ethanesulphonyl chloride (8.4 ml.) during 20 minutes. After a further 4 hours at 0-5 C. the solution was diluted with water (250 ml.), stirred for minutes and the solid was collected, washed with water and dried. It was recrystallised from chloroform/methanol to give prednisolone ZI-ethanesulphonate, M.P. 196 (dec.), +115 (5% methanol in chloroform). This compound (20 g.) was added to acetyl nitrate prepared from fuming nitric acid (40 ml.), acetic anhydride (160 ml.) and glacial acetic acid (200 ml.), and stirred at 03 C. for 3 hours. The solution was slowly poured into icewater (2000 ml.), the mixture was stirred for minutes and left to stand overnight at 0 C. The solid was collected, washed with water and dissolved in methylene chloride (500 ml.). The extract was washed with aqueous sodium bicarbonate, then water, concentrated to 150' ml. and diluted with benzene (300 ml.). The solution was distilled (to head temp. 75 C.) and the crystals which separated were collected, washed with benzene and airdried to give a benzene solvate of prednisolone 21-ethanesulphonate llB-nitrate, M.P. l9019l C. (dec.), [ot] +l45 (chloroform). (Found (percent): C, 56.1; H, 6.4; N, 2.2. C H NO S, /eC H requires (percent): C, 56.5; H, 6.3; N, 2.7.

A mixture of this compound (1 g.), sodium iodide (2 g.) and glacial acetic acid ml.) was stirred at room temperature for 1 hour, the iodine was discharged with 5% aqueous sodium bisulphite and the solution was diluted with ice-water to give a crystalline solid. The solid was collected, washed with Water and dried to give 21- deoxyprednisolone ll 8-nitrate, M.P. 145146 C.

This compound was converted into 2l-desoxyprednisolone llfi-nitrate 17a-propi0nate and finally reduced to 21- desoxyprednisolone 17a-propionate as described in Example 1.

EXAMPLE 17 A solution of p-toluenesulphonic acid (100 mg.) in benzene (50 ml.) was distilled to a volume of ml., 2l-desoxyprednisolone IIB-nitrate (0.5 g.) and propionyl chloride (1 ml.) were added and the mixture was refiuxed for 18 hours. The cooled solution was stirred with ammonium hydroxide (SG 0.88, 3 ml.) and water (12 ml.) at room temperature for minutes. The benzene layer was collected, washed with water, evaporated to dryness and the residue recrystallised from ethyl methyl ketone to give 21-desoxyprednisolone llfi-nitrate 17a-propionate, M.P. 207-209 C. (dec.), which was identical with the material prepared by the process of Example 1.

EXAMPLE l8 Prednisolone 21-iodide llfi-nitrate (2 g.), prepared as described in Example 12, was added to a solution of ptoluenesulphonic acid mg.) in propionic anhydride (40 ml), the mixture was diluted with chloroform (28 ml.) and then refluxed for 21 hours. The cooled solution was stirred with water (16 ml.) and ammonium hydroxide (SG 0.88, 8 ml.) for 15 minutes, the chloroform layer was collected, washed with aqueous sodium bicarbonate, aqueous sodium bisulphite, then Water, and evaporated to give crude prednisolone 21-iodide llfi-nitrate 17u-propionate.

This crude intermediate (0.8 g.) in dioxan (40 ml.) was stirred for 4 hours with 10% aqueous sodium bisulphite (16 ml.). The solution was diluted with water ml.), seeded and the crystals were collected, washed with water and dried. The compound was recrystallised from methylene chloride/acetone to give 21-desoxypredinsolone llfl-nitrate 17u-propionate, M.P. 2112l2 C. (dec.). This compound was reduced to 21-desoxyprednisolone 17a-propi0nate as described in Example 1. The crude intermediate was also reduced to 21-desoxyprednisolone 17a-propionate in a single stage process using zinc dust and acetic acid.

EXAMPLE 19 A mixture of trifiuoroacetic anhydride (6 ml.) and cyclopentanecarboxylic acid (4 ml.) was left to stand at room temperature for 30 minutes and then stirred with a solution of 21-desoxyprednisolone llfi-nitrate (2 g.) in chloroform (28 ml.) for 18 hours. The cooled solution was treated with ammonium hydroxide (SG 0.88, 15 ml.) and water (30 ml.) for 30 minutes, left to stand at room temperature for 1 hour and the solvent layer was collected. It was washed with aqueous sodium bicarbonate then water, dried and evaporated. The residual gum was purified by adsorption on Florisil and elution with chloroform, the extract being evaporated to give a gum.

A solution of this gum (2 g.) in methylene chloride (10 ml.) was stirred at 75 C. with zinc dust (10 g.) during the addition of acetic acid (2.7 ml.) in methylene chloride (10 ml.) over 10 minutes. After stirring for 20 minutes at 1013 C., the mixture was filtered, the solvent layer was collected, washed with aqueous sodium bicarbonate, then water, dried and evaporated. The product was purified by adsorption on Florisil, eluting with 10% acetone in chloroform and concentrating the eluate to 34 ml. The concentrate was diluted with ether and the crystals which separated were collected and recrystallised from acetone to give 21-desoxyprednisolone 17a-cyclopentanecarboxylate, M.P. 265-267 C., +30 (chloroform). (Found (percent): C, 73.6; H, 8.5. C H O requires (percent): C, 73.6; H, 8.2.)

In a similar way, using the appropriate mixed anhydride of trifiuoroacetic acid there was prepared:

2l-desoxyprednisolone 17oz cyclohexanecarboxylic 11,8-

nitrate. (Found (percent): C, 66.7; H, 7.5; N, 2.5. C2gH3qNO7 requires (percent): C, 67.3; H, 7.5; N, 2.8

EXAMPLE 20 A solution of p-toluenesulphonic acid (1.35 g.) in propionic anhydride ml.) was diluted with chloroform (945 ml), 2l-desoxyprednisolone llfl-nitrate (67.5 g.) was added and the mixture was refluxed for 16 hours. The cooled solution was added to ammonium hydroxide (SG 0.88, 270 ml.) and water (540 ml.) cooled in ice, stirred for 4 hours and the organic phase was collected. It was washed with aqueous sodium bicarbonate then water, dried and evaporated. The residue was dissolved in methylene chloride (500 ml), acetone (500 ml.) was added'and the mixture was distilled until-a thick slurry remained. The mixture was cooled, the crystals were collected, washed with acetone then ether and dried to give 2l-desoxyprednisolone llfl-nitrate l7a-propionate, identical with the material produced by the method described in Example 1.

The compound was converted into 21-desoxyprednisolone 17a-propionate as described in Example 1.

EXAMPLE 21 A mixture of 2l-desoxyhydrocortisone 17a-propionate (418 mg), prepared as in Example 1, chloranil (765 mg.) and t-butanol (28 ml.) was refluxed for 24 hours, cooled, filtered and the filtrate evaporated to dryness in vacuo. The residue was dissolved in chloroform, washed with dilute sodium hydroxide solution and water, dried and evaporated to dryness. The residue was purified by preparative layer chromatography and crystallised from ethyl acetate to give 6-dehydro-2l-desoxyhydrocortisone 17apropionate, M.P. 255-258 C., [04 I-60 (chlorm form). (Found (percent): C, 72.3; H, 8.3. C H O requires (percent): C, 72.0; H, 8.1.)

EXAMPLE 22 A mixture of 6 dehydro 21 desoxyhydrocortisone Not-propionate (312 mg.), prepared as in Example 21, 2,3 dichloro 5,6 dicyanobenzoquinone (312 mg.) and dioxan (13 ml.) was refluxed for 24 hours, cooled, filtered and the residue washed with chloroform. The filtrate was adsorbed on Florisil, eluted with methylene chloride and then 10% acetone in methylene chloride and the eluate was evaporated. The residue was purified by preparative layer chromatography and crystallised from methanol to give 6 dehydro 21 desoxyprednisolone Nor-propionate. M.P. 263265 C., [u] 2.7 (chloroform). (Found (percent): C, 72.8; H, 7.4. C H O requires (percent): C, 72.4; H, 7.6.)

EXAMPLE 23 A mixture of 21 desoxy 16oz methylhydrocortisone Hot-propionate (229 mg), prepared as in Example 1, 2,3 dichloro 5,6 dicyanobenzoquinone (229 mg.), oxalic acid (23 mg.), trichloroethylene (9.2 ml.) and ethyl acetate was refluxed for 23 hours, cooled, washed with dilute sodium hydroxide solution then water, dried and evaporated. The residue was purified by preparative layer chromatography and crystallised from ethyl acetate to give 21 desoxy 16a methylprednisolone 17ozpropionate, M.P. 258-265" C., [011 +23 (chloroform). (Found (percent): C, 72.4; H, 8.0. C H O requires (percent): C, 72.5; H, 8.3.)

EXAMPLE 24 1,9(11) 4 bisdehydro 170; hydroxyprogesterone (2 g.) was added to a solution of p-toluenesulphonic acid (40 mg.) in propionic anhydride (4 ml.) diluted with chloroform (28 ml.), and the mixture was refluxed overnight. The cooled solution was stirred with water (16 ml.) and ammonium hydroxide (86 0.88, 8 ml.) for 1% hours, the organic phase was collected, washed with aqueous sodium bicarbonate solution and then water and dried. The solvent was evaporated and the residual oil was crystallised from methanol to give 1.9(11) bisdehydro 17a propionoxy progesterone, M.P. 199203 C., 30.5 (chloroform). (Found (percent): C, 75.4; H, 7.5. C H O requires (percent): C, 75.4; H, 7.9.)

A solution of this compound (1.46 g.) in methylene chloride (25 ml.) and t-butanol (40 ml.) was treated successively at 27 C. with a solution of 72% perchloric acid (0.6 ml.) in water (3 ml.) and a solution of N- bromacetamide (0.65 g.) in t-butanol (10 ml.). After 15 minutes a solution of sodium sulphite heptahydrate (1.6 g.) in water (8 ml.) was added, and the mixture was poured into water. The product was extracted into methylene chloride, the solvent was evaporated at 40 C. and the residue was recrystallised from acetone/hexane to give an acetone solvate of 9a-bromo-21-desoxyprednisolone Not-propionate M.P. 191 C. (dec.), +71 (chloroform). (Found (percent): C, 60.3; H, 7.2; Br, 14.4. C H BrO (C H O) requires (percent): C, 60.4; H, 7.1; Br, 14.4.)

A solution of the above solvated compound (520 mg.) and butane-l-thiol (1.1 ml.) in dimethylsulphoxide (17 ml.) was deoxygenated by blowing nitrogen through the solution and then stirred with chromous acetate (700 mg.) under nitrogen overnight. The purple solution was poured into ice-water (200 m1.) and extracted with methylene chloride. The extract was washed with dilute aqueous sodium bicarbonate and then water and dried. The solvent was evaporated and the residual oil was triturated with ether to give a yellow solid. This was purified by preparative thin layer chromatography and finally crystallised from methylene chloride/ether to give 16 21-desoxyprednisolone Hot-propionate, M.P. 231-232.5 0, identical with that prepared by the method described in Example 1.

EXAMPLE 25 A mixture of 1,9(11) bisdehydro 17a hydroxyprogesterone (2.5 g.), methylene chloride (50 ml.) and t-butanol ml.) was stirred at 27 C. and treated successively with 72% perchloric acid (1.2 ml.) in water (6 ml.), and N-bromacetamide (1.3 g.) in t-butanol (20 ml.). After 15 minutes, sodium sulphite heptahydrate (3.2 g.) in water (16 ml.) was added and the mixture was poured into water. The solid was collected, washed and dried to give 2l-desoxy-9a-bromoprednisolone, M.P. 203 C. (dec.).

This compound (960 mg.) was added to a solution of p-toluenesulphonic acid (20 mg.) in propionic anhydride (2 ml.) and chloroform (14 ml.) and the mixture was refluxed for 18 hours. The suspension was filtered, the filtrate was evaporated in vacuo and light petroleum (B.P. 40-60 C., ml.) was added to the residue. The gummy solid was collected, purified by preparative thin layer chromatography and crystallised from ethyl acetate to give 21-desoxy-9a-bromoprednisolone 17u-propionate, M.P. 180 c. (dec)., [31 +80.5 (chloroform). (Found (percent): C, 60.4; H, 6.2; Br, 16.6. C H BrO requires (percent): C, 60.1; H, 6.5; Br, 16.7.) It was converted into 2l-desoxyprednisolone 17a-propionate as described in Example 24.

EXAMPLE 26 A mixture of prednisolone ZI-methanesulphonate 17a propionate mg.), sodium iodide 100 mg.) and dimethylformarnide (5 ml.) was refluxed for 30 minutes, evaporated to dryness in vacuo and the residue was triturated with 5% aqueous sodium metabisulphite. The solid was collected, dried and the major component, 21- desoxyprednisolone Not-propionate, M.P. 226229 C., was isolated by preparative layer chromatography and crystallisation from ether.

EXAMPLE 27 A mixture of prednisolone 21-methanesulphonate 17apropionate (847 mg.), sodium iodide (847 mg.) and acetone (20 ml.) was refluxed for 70 hours, cooled and poured into water. The mixture was extracted with methylene chloride, and the extract was washed, dried and evaporated. The residual gum was purified by preparative layer chromatography and crystallised from acetone/hexane to give prednisolone 21-iodide 17a-propionate. M.P. 163-165 C. (dec.), M1 104 (chloroform). (Found (percent): C, 55.5; H, 5.9; I, 24.1. C H l0 requires (percent): C, 54.8; H, 5.91; I, 24.1.)

A solution of this compound (40 mg.) in dioxan (2 ml.) was treated with 10% aqueous sodium metabisulphite (0.8 ml.) and left to stand for 2 hours. The solution was diluted with water, the solid which separated was collected and recrystallised from ether to give 21-desoxyprednisolone Hot-propionate, identical with authentic material.

EXAMPLE 28 Prednisolone 21-iodide Not-propionate (50 mg.), prepared as in Example 27, in methylene chloride (2 ml.) was stirred at 1011 C. with zinc dust (250 mg.) during the dropwise addition of glacial acetic acid (0.07 ml.) in methylene chloride (0.5 ml.). After 10 minutes at 69 C. the mixture was allowed to warm to room temperature, filtered and the filtrate was washed with aqueous sodium bicarbonate solution, then water and dried. The solvent was evaporated and the residue was crystallised from acetone/hexane to give 21-desoxyprednisolone 17apropionate identical with authentic material.

17 EXAMPLE 29 A water miscible cream was prepared containing the following ingredients (percent w./w.):

Percent 21-desoxyprednisolone 17a-butyrate 0.1 White soft paraffin 15.0

Cetomacrogol emulsifying wax 9.0 Liquid parafiin 6.0 Chlorocresol 0.1 Water 69.8

EXAMPLE 30 An ointment was prepared containing the following ingredients (percent w./w.):

Percent 21-desoxyprednisolone17a-propionate 0.1 Methyl p-hydroxybenzoate 0.02 Butyl p-hydroxybenzoate 0.18 Wool fat 10.0 White soft paraffin To 100 EXAMPLE 31 An oil-in-water cream was prepared containing the following ingredients:

Percent 2l-desoxyprednisolone 17a-propionate 0.1 Cetamacrogol 1000 1.8 Cetostearyl alcohol 7.2 White soft parafiin 15.0 Liquid paraffin 6.0 Sodium citrate 0.7 Citric acid 0.5 Chlorocresol 0.15 Purified water 68.55

EXAMPLE 32 Antibacterial oil-in-water creams were prepared with similar compositions to that of the cream described in Example 31, but in which:

EXAMPLE 33 An ointment was prepared containing the following ingredients:

Percent 21-desoxyprednisolone 17a-propionate 0.1 Wool fat 10.0 White soft parafiin To 100 EXAMPLE 34 Antibacterial ointments were prepared with similar compositions to that of the ointment described in Example 40, and containing also 0.1% of 2-bromo-2-nitropropane- 1,3-diol, 0.75% or 1.5% of 5,7-dichloro-S-hydroxyquinoline, 3% of -chloro8-hydroxy-7-iod0quin0line or 0.5% of neomycin sulphate.

EXAMPLE 35 An ear drop was prepared by dissolving ZI-desoxyprednisolone 17a-propionate 0.1% w./w. in propylene glycol.

EXAMPLE 36 An aerosol spray was prepared by dissolving 21-desoxyprednisolone 17oz-PIOP1OI18I6 in industrial methylated spirit and hexylene glycol and adding chlorofiuoroalkane propellants to give a composition containing the following ingredients:

Percent 21-desoxyprednisolone17a-propionate 0.1 Industrial methylated spirit 29.9 Hexylene glycol 10.0 iFreon 11 30.0 Freon 12 30.0

EXAMPLE 37 An aerosol quick-breaking foam preparation was prepared containing the following ingredients:

Percent 21-desoxyprednisolone17a-propionate 0.1 Polawax 0.3 Industrial methylated spirit 49.6 Hexylene glycol 10.0 Purified water 30.0 Freon 6.0 Freon 114 4.0

We claim:

1. A process for preparing a compound of Formula I in which the bonds marked are each selected from the group consisting of single and double bonds; A is selected from the group consisting of and C wherein R is selected from the group consisting of acyloxy, fluorine, chlorine or methyl; R is selected from the group consisting of hydrogen, fluorine, methyl and fluorinated methyl; and R is selected from the group consisting of alkyl, halogenated alkyl, alkoxyalkyl, aralkyl, cycloalkyl, alkenyl, aryl and heterocyclic; which process comprises treating a compound of Formula II wherein R is selected from the group consisting of chlorine, bromine, alkanesulphonyloxy and arenesulphonyloxy with 'acetyl nitrate to give a compound of Formula III TH R and thereafter subjecting the compound of Formula III to a series of reactions selected from the group consisting of Formula IV 20 reducing the lip-nitrate group of the compound of Formula VI to give a compound of Formula VH IV treating the compound of Formula IV with an acylatand reducing R3 to hydrogen to glve compound of ing agent selected from the group consisting of acid I; and anhydrides of Formula (R CO) O, acid halides of (c) tTeaFmg the compound of Formula HI formula R COX in which X is selected from the group acylafimg agen Selected from the grOIlP consisting of chlorine and bromine, and acids of for- Q acld anhydndes of f (R2C o)20: acld mula R COOH in the presence of trifluoroacctic anlldes of formula; RZCOX 1n ll X 15 Selected 0m hYdI-ideto give acompound f Formula; the group consisting of chlorme and bromine, and

acids of formula R COOH m the presence of trifluoroacetic anhydride to give a compound of Formula VI, reducing R to hydrogen to give a compound of Formula V, and reducing the llfi-nitrate group of the compound of Formula V to give a compound of Formula I.

V 2. A process as claimed in claim 1 wherein the reduction of R to hydrogen and reduction of the llp-nitrate group in series (b) and (c) take place simultaneously.

References Cited and reducing the llfi-nitrate group compound of UNITED STATES PATENTS Formula V to give a compound of Formula I;

(b) treating the Fmmula III l 2 892 851 6/1959 Bergstrom et al. 260-397.45 acylating agent SGICCtC f m the group C0111$tlng 2 5 7 11 19 5 Barton 2 0 397 4 of acid anhydrides 'f (Rzcoho acld 3152154 10/1964 Ercoli et al. 260--397.45 lides of formula RgCOX in which X selected from the 3376193 4/1968 Elks et 167 65 group consisting of chlorine and bromine, and acids 4 252 4/1969 Weir of formula R COOH in the presence of trifluoroacetic 3297729 1/1967 fi g 4 anhydride to give a compound of Formula VI n CH R 40 OTHER REFERENCES I 2 3 Gardi et aL, Gazz. Chem. Ital. vol. 96, pages 1115-24 45 ELBERT L. ROBERTS, Primary Examiner VI US. Cl. X.R. 

